The invention relates generally to touch pads and more particularly to a multi-point touch pad data input device.
Presently, touch pads are used in a variety of applications and in various devices. They are used on computers to control the pointing device as well as videogame controllers and security system keypads, to name a few. Conventional touch pads are generally only capable of registering one touch at a time, and generally, are incapable of registering a touch unless the touch is in a specific location on the touch pad. Generally, touch pads used with computer equipment will register an initial location where the finger touches the pad, and subsequent finger movement will be related to that initial point. Furthermore, certain computer touch pads generally may contain two special places where applied pressure corresponds to clicking a left or right mouse button. Other computer touch pads sense single taps or double taps of the finger at any point on the touch pad as corresponding to clicking a left or right mouse button. Thus, the single point touch pad is mainly used as a pointing device with a computer or with a device that only registers one specifically located touch such as a keypad.
New technologies including video game systems, computers, as well as devices incorporating electronic music require the need for multi-point touch pad technology. A multi-point touch pad can detect multiple touch points simultaneously on a single touch pad. Currently, multi-point touch pad technologies include the use of fiber-optic based pressure sensing, Force Sensing Resistors™ (FSR), piezoelectric sensors and capacitive touch sensors. The aforementioned technologies allow touch pads to register multiple touches. However, specifically in the case of force sensing resistors, piezoelectric sensors and capacitive touch sensors, a touch on the touch pad will not be detected unless the sensor on the touch pad is touched directly. Consequently, if the space between sensors is touched, a touch will not be properly detected or registered.
Another desirous feature of multi-point touch pads is the ability to measure pressure as well as multiple point touches. FSRs, piezoelectric sensors and capacitive touch sensors are other types of sensors that can respond to pressure. However, they suffer the same problem as previously mentioned in measuring pressure, namely, if not touched directly, there is little response, an inaccurate response or no response from the sensors.
Thus, the aforementioned touch pads are of limited use to a user seeking to control various types of devices with precision and accuracy. Accordingly, there is a need for a multi-point touch pad that ensures that simultaneous, multiple touches may be accurately and precisely sensed and recorded. There is also a desire that multi-point touch pads can accurately and precisely sense and record the pressure that is placed by the touch.